What are Horseshoe Crab Blood Uses?

horseshoe crabs, horseshoe crab blood uses
Horseshoe Crabs mating on the beach (via Wikimedia Commons)

What are Horseshoe Crab Blood Uses and How Do They Spawn

Spawning time!


Hi, I’m Edna, a horseshoe crab. I’m not truly a crab, but an arthropod related to scorpions, spiders and ticks. I’m excited because it is the new moon. It is time for me to mate and lay my eggs in the sand. This is a big deal to us horseshoe crabs to actually come out of the water for this special event.

It’s getting dark and the tide is high-I sense it’s time to crawl out of the water. I don’t have good vision, even though I have up to 10 eyes! Although I don’t see as well as humans, my vision is one million times better at night than in the day.

My special chemicals, or pheromones, that I release into the water attract male horseshoe crabs to me in the surf. One of them latches onto my back with a special claw. It’s almost time to lay my eggs!

I begin my climb out of the surf. Waves crash all around me until I make it to the wet sand. I climb out a little further and begin digging a hole to lay my 4,000 eggs. I dig and dig, and finally begin to deposit my eggs. The male horseshoe crab clasped to me fertilizes the eggs as they come out of me.
I finish laying my eggs in the sand, and the male detaches from me.

Where am I going?

Wait, why am I floating in the air? What happened to the sand and water? Something has grasped me. Am I doomed?


I am in a dark place. I scramble to crawl up the wall placed before me but it’s no use. My legs just keep scratching up against something, but I can’t crawl out or over it.

Lots of other horseshoe crabs are piled around me. I sense the moonlight one moment, and the next it is gone. I thought my life might end being eaten by a shark, but surrounded by my fellow horseshoe crabs in the dark?

Where am I?


I am tired after laying all those eggs, so I sleep. When I wake up I am in a bright area. It’s not the warm sun, but there is light all around. I can move all my legs, but I can’t go anywhere. I feel my blue blood being drained from me by a cord, and it’s not a good feeling.

Back home!

Soon enough I am lifted in the air and placed in the dark place again with all the other horseshoe crabs. After what feels like hours, I feel myself lifted into the air again. The warm sun is all around me. Then I am placed down on the wet sand. I’m home! I scurry into the surf and back into the water. What a night and day I’ve had!

Note: So what are horseshoe crab blood uses? Horseshoe crabs blue blood is harvested by the biomedical industry for testing of drugs and medical devices. Their blood is blue because they use copper as a carrier for oxygen, while humans use iron as a carrier of oxygen in their red blood. There are synthetic alternatives to LAL, but their use isn’t fully adopted yet.

It is unknown if all the biomedical industries actually return all the horseshoe crabs they bleed back into the wild as they may be sold for bait instead. There has been a study that horseshoe crabs that are bled and returned to the wild have altered behavior and the females less spawning attempts.

The Atlantic Horseshoe Crab is “Near Threatened” to being endangered.

Check out these websites for more information:
Biomedical bleeding may impact horseshoe crabs spawning behavior and movement

More on horseshoe crab spawning and how to donate to help them!

And check out Plankton:The Real Monsters of the Ocean

Interview With Dr. Deni Ramirez Macias, Whale Shark Researcher

Dr. Deni Ramirez Macias and a Whale Shark
Dr. Deni Ramirez Macias and a Whale Shark

Dr. Deni Ramirez Macias is a whale shark researcher based out of the Gulf of California (Sea of Cortez), Mexico. She is the director of Whale Shark Mexico (Tiburon Ballena Mexico). She started the whale shark research program in 2003 (but has been studying them since 2001). The goals of Whale Shark Mexico are research, sustainable management and environmental education.

I recently went on an expedition and met Dr. Deni Ramirez Macias. This is a paraphrased interview with her:

Cherilyn Jose (interviewer): Where did you get your doctorate degree from and what was your thesis?

Dr. Deni Ramirez Macias: I got my doctoral degree from the University of La Paz. My thesis was on the population genetics of the Gulf of California whale sharks. I found that the whale sharks return to the same area year after year. We re-sighted the whale sharks using photo identification.

CJ: How did you become interested in whale sharks? What was your first encounter with whale sharks like?

DRM: I saw dolphins and rays growing up. During my first close encounter with a whale shark, I found them to be beautiful and charismatic. I was curious about them and wanted to know more.

CJ: How much time do you spend in the field?

DRM: I spend 50% field/50% lab and administrative work. Approximately four times a month I see whale sharks in the field, and I have other researchers that go out three to four times a week.

CJ: Why should we save the whale sharks?

DRM: We should save whale sharks for the ethics of it–life will continue without us and we have to do something (before that happens). Saving whale shark habitat saves other species such as manta rays, mobula rays, and whales—it helps the ocean in general.

CJ: What are some threats to whale sharks?

DRM: Microplastics accumulate in whale sharks, not just in the adults but in the juveniles too. The same goes for heavy metals (and other pollutants). To help I use biodegradable pesticides to fumigate.

CJ: What are some future objectives of Whale Shark Mexico?

DRM: I will collaborate with other researchers in places such as Latin America. I will train locals to help sight and track whale sharks.

Note: Deni and her assistant, Maritza Cruz Castillo, are attempting to ultrasound one of the pregnant female whale sharks that frequent the Gulf of California. Stay tuned for updates!

I will also have posts on the 10 day expedition I took recently to the Gulf of California, with Panterra Expeditions and the Shark Research Institute, when I had a whale shark named after me ☺!

Plastic Bits are Food? An Anchovy’s Perspective…

anchovy, anchovies, anchovies and plastic
Anchovies:Photo credit: Erik Sorenson via Visual hunt / CC BY

Anchovies can smell plastic pieces in the ocean and mistake them for food.

Plastic bits or food-they all smell the same to me. Hi, I’m Annie, and I’m an anchovy. You may have seen my colleagues in a tin can (may they RIP), or in the ocean in a large shimmery school that’s hopefully not being eaten by large predators such as sharks and dolphins, eek!

You might also wonder how we can smell in the first place, as we live underwater. Chemicals travel through the water and into my nostrils, just like they do in the air for terrestrial animals. Sharks can smell blood from very far away or in low quantities. Salmon use their sense of smell to navigate back to their birthplace spawning ground upstream.

Back to the plastic bits-humans have found that over 50 kinds of fish mistakenly eat plastic, thinking that it’s food. That includes my friends and I. A neat study by humans using an anchovy school in an aquarium (Aquarium of the Bay in San Francisco, California) found that by measuring our schooling behavior (how tight we schooled and our body position relative to water flow) that we:

1. Use odors to locate food

2. Plastic pieces are confusing to us due to their similarity to food in appearance and smell

So what can you do to help? Avoid single use plastics (SUP) whenever possible and recycle if you do buy them! Less than 7 percent of plastic in the U.S. gets recycled. Thanks for recycling, every little bit helps! Fortunately I won’t be around in 2050 when there is more plastic in the ocean than fish…

I used information from these articles:
Bait and Switch: Anchovies Eat Plastic Because it Smells Like Prey

The Numbers on Plastics

Coral Reef Bleaching and The Great Barrier Reef

coral reefs of Great Barrier Reef, coral reef bleaching
Photo credit: FarbenfroheWunderwelt via Visual Hunt / CC BY-ND

Why are the corals on the Great Barrier Reef off of Australia bleaching? Why is coral reef bleaching important?

First a little background on corals.

Hi, I’m Polly, a coral polyp. The animal you think of as “coral” is actually made up of lots of little coral polyps. We use calcium carbonate to make our skeleton and many of us together make the base of a coral reef.

We’re only millimeters wide (0.1 inch) and centimeters deep (1.2 inches) with tentacles sticking out. We use our tentacles to find food floating in the water.

But our main source of food is made for us by our friends inside us, the zooanthellae. These are our photosynthetic symbionts. In other words, the plants inside of us use sunlight to make the food that we eat. These zooanthellae are important to us, but when exposed to stressors like increased heat or acidity, they often expel themselves from us. This causes coral reef bleaching.

Coral reef bleaching can be caused by the ocean warming due to climate change. The ocean absorbs 90 percent of the heat in the atmosphere caused by human activities. Coral bleaching can also be affected by ocean acidification. The ocean becomes more acidic (like soda or stomach acid) when it absorbs carbon dioxide from the atmosphere. There is also pollution of all sorts, including plastic, chemical, and sediments that can also cause the coral reef to bleach.

A recent scientific study found that “huge portions” of the northern end of the Great Barrier Reef died last year (2016) due to warming seawater. Just an increase of two or three degrees Fahrenheit (1.2-1.6 degrees Celsius) can cause coral reef bleaching. The southern end of the Great Barrier Reef is bleaching as we speak.

So why do we need coral reefs? Coral reefs house twenty-five percent of all marine life in the oceans.
One billion people rely on the ocean for their primary source of protein
, and many of those in developing countries rely upon coral reefs for it.

So what can you do? Here are some excerpts from the Nature Conservancy’s 10 Easy Steps to Protect Coral Reefs

1. Support businesses such as fishing, boating, hotel, aquarium, dive or snorkeling operators that protect coral reefs.
2. Practice safe snorkeling and diving practices such as not touching the coral and not anchoring on coral.
3. Volunteer on vacation to clean-up a coral reef or help plant one.
4. Plant a tree to reduce the carbon dioxide in the atmosphere.
5. Dispose of your trash (or recycle!) properly, especially near the ocean. Better yet, join a beach clean-up.

Also see Ollie the Octopus on Coral Bleaching and the Great Barrier Reef

Thank you Dr. Jane Goodall!

Today I heard Dr. Jane Goodall speak for the 5th time at the Wildlife Conservation Network Expo in San Francisco, CA. Dr. Jane is my personal role model and hero. After hearing her speak for the first time at a Bioneers Conference, a light bulb went off for me. I’m to follow in her footsteps, but for the oceans that cover 70 percent of our Earth.

Dr. Jane inspired me to found a Roots and Shoots group at my children’s school, Kitayama Elementary in Union City, CA. We were honored with group of the month many years ago.

I never tire of hearing Dr. Jane’s talks. Each is unique and inspiring. While all her speeches refer to her time studying chimpanzees in Gombe, today she surprised me and mentioned my favorite animal, the octopus. She said to google “coconut octopus” to see an example of tool use in animals.

During her book signing, I asked Dr. Jane her favorite ocean animal. She said, “I suppose whales.” I definitely don’t think she’s been asked that before! I also thanked her for mentioning my favorite animal, the octopus. I gave her a blue marble (see the blue marble project here) and my business card with my blog url on it. I said I named it in her honor (all her books have the word hope in them) and she said she’d check it out. I forgot to mention that I often write from the (non-human!) animal’s POV. I think she’d approve. Thank you Dr. Jane for continuing to inspire me and so many others to save our natural world!